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-W. P. KRAUSE. ENGINE FOR PUNCHING MACHINES.

APPLICATION FILED MAY 10. 1915- Pa-tented J me 10 2 SHEETS-SHEET I mr NnxRls Farms ca, mmmuruon WASNINDIOH. n c.

W. P. KRAUSE.

ENGINE FOR PUNGHING MACHlNES.

APPLICATION FILED MAY 10. 1915.

Patented June 10, 1919.

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WILLIAM P. KRAUSE, OF CHICAGO, ILLINOIS, ASSIGNOR T0 HANNA ENGINEERING WORKS, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ENGINE FOR PUNCI-IING-MACI-IINES.

Specification of Letters Patent.

Patented June 10, 1919.

Application filed May 10, 1915. Serial No. 27,210.

To all whom it may concern:

Be it known that I, WILLIAM P. KRAUsE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Engines for Punching- Machines, of which the following is a specification.

This invention-relates to improvements in engines for punching machines, and has for its object to provide a machine of that nature in which the punching die is actuated by a fluid actuated piston, my improved machine being provided with means to check the movement of the piston and die at the completion of its punching operation without jar or shock to the allied structure. The main object of my invention is to provide such a punching machine to which I have applied mechanism of the nature of a dash cup coacting with the piston to check its movement at the completion of the punching stroke.

These and other objects I accomplish by the structure and mechanism described in the following specification and shown in the accompanying drawings, in which- Figure 1 is a side elevation partially in section of my improved machine;

Fig. 2 is a vertical section through the cylinder and toggle mechanism;

Fig. 3 is a diagrammatic view of the lever mechanism.

Like numerals refer to like elements throughout the drawings.

10 indlcates a frame simllar 111 its construction to a riveter frame having the open:

cess or guide-way in the jaw 10, as indicated in dotted lines. Strippers 11 are attached to the jaw 10 on each side of the punch 11, as shown in the drawing. Upper toggles 16 are pivoted upon pins or trunnions 16 carried in jaws 16 of the main frame, as shown in the drawing, these upper toggles 16 depending downwardly between said aws.

toggle 14 is eccentrically located with respect to the gudgeons 15. This lower toggle 14 is operatively attached to block 13 and is arranged to reciprocate the same, as will be more fully described below. The main lever 18 is pivotally attached at its lower extremity at 18 to a piston rod 19, in turn pivotally attached at its extremity 19 to a wrist pin 20 carried by the piston 21. This piston is provided with the enlarged head 21 carrying the usual piston rings and is formed with the outwardly extending hollow trunk portion 2]. reduced in diameter to form with the enlarged head 21 the shoulder 21. The piston rod 19 extends through the hollow trunk portion 21", as is clearly shown. Radius rods 22 are provided having one extremity pivotally attached to the punch frame at 22 and the other extremity pivotally attached to the lever 18 at 22. The above described toggle and lever structure is similar in construction and operation to that shown and described in the patent to Hanna, No. 823,273, dated June 12, 1906, and forms no part of the present invention. The piston 21 is mounted in a cylinder 25, the same being provided with. one end apertured to permit reciprocation therethrough of the trunk portion 21 of the piston, this end being provided with a shoulder to pre vent the piston2l from moving entirely out of the cylinder, as will be obvious. A pack- 'ofby the tube or cylinder larger interior diameter than that of the ing head is attached to this end of the cylinder and coatts therewith "to form a gland or stuihng box to prevent leakage of actuating fluid therethrough. The piston rings perform their usual function, as will be apparent. A cylinder head 25 is secured by bolts, 01 the like, to the other end of the cylinder 25. The piston 21' is constructed to provide a clearance space at eitherend of the cylinder 25 and a valve chest 25 is provided, togethcr with Well known valve mech; anisrn" and ports to control the movement of the piston 21, all of a well known manner. The cylinder head 25 is provided with the enlarged thickened portioii'25 which is" pro vided with a cup or recess 25 internally threaded. A dash pot 26 having" a threaded reduced end' is provided, the reduced end thereof being threaded intoenga'geinent with This dash pot 26' is pro the recess 25. v vided with the cup'portion 26 and the outwardly extended upper periphery 26 internally threaded to permit enga emen't there 2? of slightly cup 26? proper. This tube or cylinder 27 is normally sealed or closed at its open end slightly enlarged adj acent its outer end to' by the cap 27 secured thereto; Theehiarg'ed" portion 25 of the cylinder head 25 is" centrally apertured at 25 and a similar 'zjtlining. aperture extends through the end' 'of the cup member 26, this aperture therein being permit projection threin'to of a packingsheetor cup .28 of leather or the like, the sameha'ving its outer periphery 28 alignlarly disposed with respect tothe" other por ticn' which projects iiito't'he aperture in the 'end of cup member 26 and fitting between the end or the'cup member 26 and the bottom of recess 25 as clearly shown, "this" cup being tightly maintained between the two members by means of the cup member 26.

The piston 21 is provided with the central boss or enlarged portion 21 apertured and threaded for insertion thereinto of the rod 29 which extends therefrom through aperture 25 and the corresponding aperture in the cup member 26 into which it projects;

This rod carries a leather packed piston; 30 arranged to closely fit the cup 2656f slightly less diameter than thatof interior of cylinder 27. A pipe or duct 31 leads from and communicates with the interior of cylinder 25, to and colnmunicates with the interior of cylinder 27 and cup 26. This p ipe oi-"duct 31 is provided with a check valve 31 to permit the actuating fluid to flow from cylinder 25 to cylinder 27 andcup' 26 as will be more fully explained.

The operation of the punching machine itself is as follows :-As'suming that metal to be punched is placed'upon' thiblock 'or anvil 2 '10 and steam or compressed air is admitted will operate, as will be apparent, to force the punch 11 downwardly toward the block 10 until punching of the metal is completed, after which the lower end of punch 11 will move downwardly in the recess or aperture 10 In the ordinary operation of these machines great pressure is required to properly actuate the piston 21 to overcome the resistance of the metal to the passage of the punch therethrough, and it has been found that when the punch has ssed through the metal, this pressure and the cessation of the resistance of the metal cause the piston 21 to hedriv with great violence against the shoulder 21 of the cylinder, whereby a jar or shock is transmitted to the whole mechanism to the detriment thereof.

I have eliminated this objection by the construction shown and described above. It will be apparent that'wh'en' the piston 21' is at the opposite end of ti'ie'oylihder' from that shown in the drawing, previousto theo'oi mehcin of punching operation, the piston 80 carried by rod 29 will be adjacent the outer end of the tube or cylinder 27. Steam or compressed air from the cylinder 25 will to flow until the small piston 30 reaches the inlet duct 32 at the comparativel great pressure necessary to perform the punching operation. As the piston 30 reaches the point mentioned at its entrance into cup 26", the'further flow of steam through pipe 31 beneath the piston 30 'wi'l'lbecut oif and the;

previously admitted actuating fluid beneath cup 26 at its initial high pressure. Further the piston 30'wi1lb'e confined thereby in the movement of the' piston 30 in unison with piston 21 results in this confined fluid being compressed to a very great pressure, as will be apparent, asthe piston SO're'aches the end of its stroke. This pressure gradually be comes so enormous that acting in resistance to. the movement of piston 30, serves to balanee the actuating pressure on piston 21 and the" latter, together with the pun'ching mechanism i'sbrou'ght to a rest just after the punch breaks through the metal andjust previous to' the completion of its stroke, without jar or injurious shock to the machine. It will be apparent that by varying the d'ii'nen'sio'ns of cup 26, piston 30 and the" alliedelements, this checking elfect may be controlled to produce the desired efiect, namely, the checking of the mechanism described above the at approximately the instant after punching is completeds v It is necessary, for the proper functioning of this checking means, to provide a packing around rod 29 where it passes through the cylinder head 25 and cup member 26 which will substantially prevent leakage of the fluid therearound. To attain this end I have provided the leather or other packing cup 28, described above, having its central portion extending into the aperture in cup 26, closely fitting around the rod 29. To increase the contact of this cup 28 with rod 29, I provide small ducts or passages 26 leading from the lower portion of cup 26 to the peripheral groove 26 around the packing cup 28, as is clearly shown in the drawings. It will be apparent that as the pressure of the fluid trapped beneath the piston 30 increases, this pressure will be transmitted through the ducts 26 to groove 26 whereby the packing cup 28 under the pressure of the fluid transmitted through said ducts will be more and more tightly pressed around and held against the rod 29, thereby increasing the prevention of leakage of the fluid which would ordinarily interfere with the proper functioning of the checking member.

It will be apparent that my invention is susceptible of many modifications and improvements, and I do not wish to be restricted to the form shown or described beyond the scope of the appended claims.

What I claim is:

1. In combination with a cylinder having a reciprocable piston, means to check the movement of said piston adjacent one limit of its travel, said means comprising a dash pot and a piston member coacting therewith, and means to introduce fluid under pressure to said dash pot intermediate the limits of travel of said piston member.

2. In combination with a cylinder having a reciproeable piston, means to check the movement of said piston adjacent one limit of its travel, said means comprising a dash pot and a piston member coacting therewith, and means to introduce fluid under pressure from said cylinder to said dash pot intermediate the limits of travel of said piston member.

3. In combination with a cylinder having a reciprocable piston, means to check the movement of said piston adjacent one limit of its travel, said means comprising a dash pot, a piston member coacting therewith and reciprocably mounted therein, a rod operatively connecting said piston member with said piston, means to prevent leakage of fluid around said rod, said means comprising a packing member, and means to provide fluid under pressure to coact with said packing member and increase its contact with said rod.

4. In combination with a cylinder having a reciprocable piston, means to check the movement of said piston adjacent one limit of its travel, said means comprising a dash pot, a piston member coacting therewith and reciprocably mounted therein, a rod operatively connecting said piston member with said piston, and means to provide fluid under pressure from said cylinder to said dash pot intermediate the limits of travel of said piston member.

5. In combination, a cylinder having a head, a piston mounted in said cylinder, a rod extending through said head and attached to said piston, a cup member attached to said head, said rod being also extended through said cap member, a piston member carried by said rod and arranged to fit and coact with said cup member to check the movement of said piston adjacent one limit of its travel, and means to introduce fluid under pressure from said cylinder to said cup member beneath said piston member intermediate the limits of travel of said piston member.

6. In combination, a cylinder having a head, a piston mounted in said cylinder, a rod extending through said head and attached to said piston, a cup member attached to said head, said rod being also extended through said cup member, a piston member carried by said rod and arranged to flt and coact With said cup member to check the movement of said piston adjacent one limit of its travel, means to introduce fluid under pressure from said cylinder to said cup member beneath said piston member and intermediate its limits of travel, a packing member having a portion fitting around said rod, and means to supply fluid under pressure from said cup member to said packing member to increase its contact with said rod.

7. In combination with a cylinder having a reciprocable piston and a head, an auxiliary cylinder carried by said first-named cylinder head, a piston member mounted in said auxiliary cylinder, a piston rod extending between and connected to said piston and said piston member, said cylinder head and auxiliary cylinder being apertured to permit passage therethrough of said piston rod, a packing member having a flanged portion surrounding said piston rod between said cylinder and auxiliary cylinder, and ducts extending from said auxiliary cylinder to supply fluid under pressure to the outer periphery of said packing flange whereby the latter will be closely pressed against said piston rod.

8. In combination with a cylinder having a reciprocal piston and a head, an auxiliary cylinder carried by said first-named cylinder head, a piston member mounted in said auxiliary cylinder, a piston rod extending between and connected to said piston and said piston member, said piston head and zmxsaid auXiliary cylinder during a portion of iliary cylinder being apertured to permit the stroke of said piston member-.. 10 passage therethrou'gh of said;- pistan'rnd, and In testimony whereof, I have subscribed a duct leadingfrom said main cylinder to my nam'; said auxiliary cylinder at a, point interme WILLIAM P. KRAUSE; diate the limits of travel of said piston Witnesses:

member whereby fluid under pressure will ARTHUR I. JENSEN,

be transmitted from said main cylinder to PHILETUS W. GATEs.

Copies of this patent may be obtained for five dents each; by add'fe'ssing tHe' flommi'ssirgnef of Patents; Washington, D. 0. 

